mysql_connect() yerine mysqli_connect() veya PDO

Mesela mysqli
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

// mysqli bağlantısı
$conn = mysqli_connect($servername, $username, $password, $dbname);

// Bağlantı kontrolü
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
echo "Connected successfully";

PDO
$dsn = "mysql:host=localhost;dbname=database;charset=utf8 mb4";
$username = "username";
$password = "password";

try {
$pdo = new PDO($dsn, $username, $password);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
echo "Connected successfully";
} catch (PDOException $e) {
echo "Connection failed: " . $e->getMessage();
}

Duzeltirseniz bu şekilde çözülebilir.